UNITED STATES PATENT OFFICE.

PETER ALVERSON, OF NEW HAVEN, CONNECTICUT. SPRING-LOCK FOR COACH
AND RAILROAD-CAR DOORS, &c.

Specification of Letters Patent No. 666, dated April 2, 1838.

To all whom it may concern:

Be it known that I, Peter Alverson, of New Haven, in the county
of New Haven and State of Connecticut, have invented a new,
improved, and useful Spring-Lock for Coach and Railroad-Car
Doors.

The object of my invention is a spring lock, easily managed and
of sufficient strength to secure the door firmly, and yet in size
and form so compact, as not to injure the pillar of the door, nor
interfere with the run of the lights, and which may be opened or
shut from within as well as from without.

This I effect by a mortise lock, the ordinary size of which,
exclusive of the face plate, is less than two inches long, one
inch deep and about � of an inch thick, and consists of the
following parts, viz: The face plate, the bolt, a double spiral
spring, and stud, the tumbler, the base or shell, and the spindle
with knobs or handles.

To enable others skilled in the art to make and use my invention,
I describe the form of construction and operation of my lock as
follows, referring to the drawings accompanying this my
specification as part thereof, for a more full illustration.

No. 1 A represents the face plate, about three inches long, with
mortises for the bolt, for the end plates of the case, and for
screws to hold the lock in place. No. 2. B the side plates of the
case, with an orifice in each for the ends of the tumbler to play
in. No. 3. C exhibits the back plate of the case, with an orifice
at X to receive a stud half an inch long to be firmly riveted in
place, for the spiral spring to play upon. No. 4. D the end
plates with tenons and dovetails. No. 5 represents the back
plate, stud, spiral spring and bolt in connection A, the back
plate. B, the stud within the spring C. C, spiral spring; this
may be single, but I prefer a double spiral spring with reverse
twists one within the other. D, the bolt one inch long � broad
and is an inch thick, armed with a shoulder, a, on one side to
check its projection through the face plate and an other shoulder
at b, forming the segment of a circle for the lever of the
tumbler to operate upon. These shoulders permit the bolt to
project through the plate half an inch, exhibiting a head � broad
and � thick, with a face beveled to slide easily on the
stretcher. From the center of the back end of the bolt I drill a
hole half an inch or more deep of sufficient size to receive the
spring with easy play as seen by the dotted lines x. No. 6
exhibits the inside of the lock incased by a side plate being �
thereby showing the tumbler A, and other parts in place, and
their operation. The body of the tumbler is a shouldered cylinder
compassing through the lock, having the necks fitted to play in
the orifice of the side plates, and having a square hole, �, in
the center for the spindle and being carried with a wing-lever b,
firmly attached to the body of the tumbler by brazing or
otherwise, and fitted to play upon the circular shoulder of the
bolt.

The several parts thus described are put together in the
following manner. The side and end plates, inclosing the tumbler,
are riveted and brazed to the face plate. The back plate with the
stud, spring and bolt connected as seen in No. 5 is then put in
place and firmly riveted as seen in No. 6, and the operation is
as follows.

The double spiral spring is calculated for an expansion of about
two inches and a contraction to half an inch, and is placed upon
the stud of the back plate so that one end of the spring shall
press upon the plate and the other end upon the bottom of the
hole in the bolt and thereby force the head of the bolt to
project. By turning the tumbler to the left, the lever will press
upon the circular shoulder, and draw back the bolt to the bottom
of the case. The body of the bolt passing over and embracing the
contracted spring and stud, thereby depressing with little
friction, the projected head of the bolt to the level of the face
plate. The bolt is steadied in its movement and supported on
three sides by the case and on the other by the body of the
tumbler.

No. 8, exhibits the lock in place, in the pillar of the door,
with spindle and knobs attached, viz: A, the face plate of the
lock. B, the knob or handle on the outside. C, the inside knob
attached to the spindle by a crank, thereby carrying the knob so
far back as to prevent interference with the standing pillar when
closing the door. The means of opening the door from within is
not a necessary appendage to my lock. It may be used without, but
when desired for the greater safety or convenience of passengers
in cars or coaches, the mode suggested may be adopted. D, D, of
No. 8 by dotted lines shows the place of thimble collars half an
inch or more deep, made with a screw thread and lip on the
outside, to arm the hole in the pillar of the door for the
spindle to play in, and when screwed in, are by the thread of the
screw held firmly in place, and are an improvement on the collars
in use.

For the materials of this lock, I propose to make the bolt and
the body of the tumbler of brass, the case and lever of sheet
iron.

But all parts of the lock except the lever on the tumbler, which
ought to be made of iron, and all the other parts may be made of
brass, or any other suitable metal.

The superior advantages of this lock over any other coach lock in
use, consists in its firmness, easy management, and its compact
form adapting it to its appropriate use for coaches and railroad
cars; but it may be applied to closet and other doors of houses.

I claim as my invention and improvement:

1. The mode or method of inserting the spring, so as to permit
the body of the bolt to pass over it, thereby lessening the space
required for the bolt, in the manner specified.

2. I claim the construction of the lever in combination with the
bolt constructed as above described.

New Haven, March 9th, 1838.

PETER ALVERSON.

Witnesses: Simeon Baldwin, Julius Austin.